#include <stdio.h>
#include <stdlib.h>

int main()
{
    FILE *pf=fopen("data.in.text","r");
    if(pf==NULL)
    {
        perror("fopen");
        return 1;
    }
    int ch;
    while((ch=fgetc(pf))!=EOF)
    {
        if(ch>='A'&&ch<='Z')
        {
            printf("%c",ch-'A'+'a');
        }
        else
        printf("%c",ch);
    }
    fclose(pf);
    pf=NULL;
    return 0;
}
